采用等离子熔覆技术在高锰钢表面原位反应制备了低碳Fe-Cr-Ni合金涂层.利用金相显微镜、扫描电镜和x射线衍射仪分析了熔覆层和热影响区的显微组织、形貌以及相组成,讨论了它们的形成机制,并用摩擦试验机测试了涂层和基体的耐磨性.结果表明,制得的Fe-Cr-Ni合金涂层无裂纹,与基体表现为冶金结合,由γ(Fe-Cr-Ni固溶体)相与M7C3等碳化物组成.根据v相形貌,熔覆层组织由上到下依次为等轴晶、树枝晶、胞状晶和平面晶.热影响区组织为魏氏体.基体为奥氏体和少量珠光体组织.Fe-Cr-Ni合金涂层的显微硬度最高为723 HV,约为基体的3倍.涂层的磨损量远小于基体的磨损量,Fe-Cr-Ni合金涂层可显著改善高锰钢的硬度和耐磨性.%A Fe-Cr-Ni alloy coating with low carbon content was fabricated on the surface of high-manganese steel via in-situ reaction by plasma cladding.The microstructure,morphology and phase composition of the cladding layer and heat-affected zone were studied by metalloscope,scanning electron microscope and X-ray diffractometer.The formation mechanism of the alloy coating was discussed.The wear resistance of the coating and substrate was examined by friction tester.The results showed that the Fe-Cr-Ni alloy coating obtained is crack-free and metallurgically bonded to the substrate,and consists of γ phase (Fe-Cr-Ni solid solution),M7C3,and some other carbides.The cladding layer is composed of equiaxed crystal zone,dendrite zone,cellular crystal zone and planar crystal sequentially from surface to bottom according to the morphology of γ phase.The microstructure of heat-affected zone is Widmanstatten structure and the substrate is of austenite structure with a small amount of peaflite.The maximum microhardness of the Fe-Cr-Ni alloy coating is 723 HV,which is three times more than that of the substrate.The wear loss of the coating is much smaller than that of the substrate,indicating that the hardness and wear resistance of high-manganese steel are greatly improved by the Fe-Cr-Ni coating.
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